Relative therapeutic efficacy of (125)I- and (131)I-labeled monoclonal antibody A33 in a human colon cancer xenograft Journal Article

  


Authors: Barendswaard, E. C.; Humm, J. L.; O'Donoghue, J. A.; Sgouros, G.; Finn, R. D.; Scott, A. M.; Larson, S. M.; Welt, S.
Article Title: Relative therapeutic efficacy of (125)I- and (131)I-labeled monoclonal antibody A33 in a human colon cancer xenograft
Abstract: A33, a monoclonal antibody that targets colon carcinomas, was labeled with I-125 or I-131 and the relative therapeutic efficacy of the 2 radiolabeled species was compared in a human colon cancer xenograft system. Methods: Nude mice bearing human SW1222 colon carcinoma xenografts were administered escalating activities of I-125-A33 (9.25-148 MBq) or I-131-A33 (0.925-18.5 MBq), I-125- and I-131-labeled control antibodies, unlabeled antibody, or no antibody. The effects of treatment were assessed using the endpoints of tumor growth delay and cure. Results: Tumor growth delay increased with administered activity for all radiolabeled antibodies. Approximately 4.5 times more activity was required for I-125-A33 to produce therapeutic effects that were equivalent to those of I-131-A33. This ratio was approximately 7 for a nonspecific, noninternalizing isotype-matched, radiolabeled control antibody. Unlabeled A33 antibody had no effect on tumor growth. Approximately 10 times more activity of I-125-A33 produced toxicity similar to that of I-131-A33, and this ratio fell to approximately 6 for radiolabeled control antibody. Conclusion: Treatment with I-125-A33 resulted in a relative therapeutic gain of approximately 2 compared with I-131-A33 in this experimental system.
Keywords: toxicity; radioimmunotherapy; efficacy; cells; therapeutic; phase i/ii; targeting; radionuclides; group no 6; radiolabeled mab a33; colon cancer xenograft; emitter
Journal Title: Journal of Nuclear Medicine
Volume: 42
Issue: 8
ISSN: 0161-5505
Publisher: Society of Nuclear Medicine  
Date Published: 2001-08-01
Start Page: 1251
End Page: 1256
Language: English
ACCESSION: WOS:000170311300021
PROVIDER: wos
PUBMED: 11483688
Notes: Article -- Source: Wos
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MSK Authors
  1. George Sgouros
    146 Sgouros
  2. Elsie C Barendswaard
    13 Barendswaard
  3. Ronald D Finn
    279 Finn
  4. Joseph O'Donoghue
    151 O'Donoghue
  5. John Laurence Humm
    434 Humm
  6. Steven M Larson
    959 Larson
  7. Sydney Welt
    98 Welt
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